Improvement of Total Etching Dentin Bonding with Subpressure

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Biomaterials Engineering

Background:

• Total-etching adhesives are widely used in restorative dentistry.
• Optimizing the bond between adhesives and dentin is crucial for long-term restoration success.
• Factors influencing adhesive penetration and bond durability require further investigation.

Purpose of the Study:

• To investigate the impact of subpressure application on the bond properties of total-etching adhesives to dentin.
• To evaluate the effects of varying subpressure levels on microtensile bond strength (μTBS), nanoleakage, and failure modes.
• To determine if subpressure can improve the interfacial integrity of bonded dentin.

Main Methods:

• Thirty-six caries-free premolars were used, divided into a control group and three subpressure groups (0.8, 0.6, 0.4 bar).
• Adhesives were applied, followed by resin bonding. Specimens were subjected to water storage or thermocycling.
• Microtensile bond strength (μTBS), failure modes, nanoleakage, and SEM imaging of resin tags were evaluated.

Main Results:

• Subpressure groups exhibited longer and denser resin tags compared to the control.
• μTBS was significantly higher in subpressure groups (p < 0.05).
• Subpressure groups showed predominantly mixed failures and reduced nanoleakage (less silver deposition) compared to the control group.

Conclusions:

• Subpressure application is a promising technique to enhance the bonding of total-etching adhesives to dentin.
• This method improves resin tag formation, leading to increased bond strength and reduced interfacial degradation.
• Subpressure application may significantly improve the longevity and reliability of dental restorations.